1. Technical Field
The present disclosure relates to an LED lamp incorporating an LED chip serving as a light source.
2. Related Art
LED lamps using LED chips as a light source having far less power consumption have recently been commercially available in markets. One of types of LED lamps generally includes a metal heat dissipator made of a metal, such as aluminum, having high heat conductivity, a cap mounted to an end of the heat dissipator, a module substrate on which an LED chip is mounted, a glove having a semispherical top and made of translucent glass or plastic material and a lighting circuit which supplies electric power to the LED chip. The module substrate is fixed to an end of the heat dissipator located opposite the cap. The glove is mounted to the heat dissipator so as to cover the module substrate. The lighting circuit is incorporated in the heat dissipator. The lighting circuit is electrically connected to the cap and further to the module substrate. This type of LED lamp is disclosed by Japanese Patent Application Publication Nos. JP-A-2011-70972, JP-A-2011-82132, JP-A-2011-90828 and JP-A-2011-91033.
The aforementioned LED lamp is used as a substitute for incandescent lamps substantially solely and its use is accordingly limited. The LED chip serving as the light source for the LED lamp has an exceedingly lower calorific value during its turn-on time as compared with the filament. Accordingly, the temperature of the heat dissipator rises only to about several dozen degrees at the highest during the turn-on time of the LED chip. Thus, the LED lamp has such a characteristic that the temperature thereof is low such that the LED lamp can be touched during its turn-on time.